As the oxidation reaction of an organic compound applied to production of an epoxy compound by oxidation of olefins, production of aldehydes and ketones by oxidation of alcohols, and the like, there is known a reaction using hydrogen peroxide as an oxidizing agent and carried out in a two phase heterogeneous system composed of an organic phase containing a dissolved organic compound as an oxidation subject, and of a aqueous hydrogen peroxide solution. Further, there is also suggested a specific catalyst for improving the conversion rate of olefins and the selectivity of an epoxy compound in this reaction.
For example, patent document 1 discloses a method of carrying out epoxidation by reacting olefins and aqueous hydrogen peroxide with a halogenated hydrocarbon as a solvent, using a catalyst such as polyacids and the like. This method, however, has a problem of use of a halogenated hydrocarbon harmful for earth environments. As a method using no halogenated hydrocarbon, patent document 2 discloses a method of oxidizing olefins with aqueous hydrogen peroxide, in the presence of α-aminomethylphosphonic acid, tungstic acids and phase transfer catalyst, in a non-halogenated organic solvent such as aromatic hydrocarbons and the like.
However, these methods have problems that when hydrogen peroxide of high concentration is used, an intensive reaction accompanied by heat generation tends to occur, there is a necessity of use of aqueous hydrogen peroxide of low concentration for safety, and recovery of a catalyst after the reaction and treatment of waste water after the reaction become difficult, and the like. Further, in these methods, the yield of the product (selectivity×conversion rate) is also unsatisfactory. That is, the oxidation reaction of an organic compound carried out in a two phase heterogeneous system composed of an organic phase and a hydrogen peroxide aqueous solution has problems from the standpoint of earth environments and from the industrial standpoint.
As a method for solving this problem, patent document 3 discloses a method of oxidizing olefins using a urea-hydrogen peroxide powder as an oxidizing agent, in a powdery dispersion medium composed of hydrotalcites, using polyacids or specific metal oxides as a catalyst. This method is carried out in a solid phase, and has merits that an organic solvent exerting a reverse influence on earth environments is not required, the conversion rate and selectivity are high, reuse of a catalyst is possible, and the like.
(Patent document 1) JP-A No. 62-234550
(Patent document 2) JP-A No. 8-27136
(Patent document 3) JP-A No. 2005-104902